in his second inaugural address, president obama pledged to address the threat of climate change. well, he's got the attention of a few folks, because yesterday tens of thousands of americans gathered on the national mall in washington, d.c. to urge him to keep his word. an estimated 35 to 50,000 protesters participated in the forward on climate rally in what was billed as the largest climate rally in american history. now, the crowd marched to the white house in opposition to the upcoming keystone xl pipeline decision. the project environmentalists say would cause irreparable damage to our climate. they say the extraction and production of tar sands oil causes actually more emissions than conventional crude. and public water fly supplies, croplands, and recreational opportunities will all be at risk of dangerous tar sands oil spills. president obama's decision on whether to approve the keystone xl pipeline will really be his first major climate change decision during his second term. many of the folks at the rally, including senator sheldon whitehouse were there to show their sup